1. Field of Invention
This invention relates to a portable sanding machine which contains three motors which provide suction to remove debris, elect-magnetic vibrations to cleanse the filter springs and gyration to turn a driver cable and generate the spinning action of the abrasive head. This head is connected to the base unit via a hose which simultaneously transports the debris to a collection unit and houses a separate self-contained hose, containing lubrication, in which a driver cable is enclosed to turn the abrasive head.
2. Description of Prior Art
Heretofore many different arrangements were used to collect debris generated during the sanding process. These arrangements were very inefficient, costly and did not fully address the health concerns of the workers using this type of equipment. It is important to collect as much debris as possible, generated by the sanding process, so that it can not be breathed in by the user.
One arrangement which focuses upon the issue of improved collection capacity is Nishio, U.S. Pat. No. 5,713,785 (1998). It employs a special skirt member, located at its bottom edge, to sand a wider surface. It moves freely up and down the outer periphery of the body of the abrasive member and consequently incurs substantially more wear and tear than the inner portion. Although this configuration prevents less damage to the main sander body, it does not capture any more debris than a normal suction head.
Another arrangement, shown in Schuster, U.S. Pat. No. 3,872,627 (1975), utilizes a movable wall which serves as a damper to prevent the suction of foreign matter into the collector bag. This wall divides the discharge end of the duct supplying the air from the entry point of the suction duct thus diminishing the accumulation of foreign matter. Although this process decreases the likelihood of foreign matter igniting the contents of the collection bag, it does not filter out the smaller debris which escape into the air during the sanding process.
Robert, U.S. Pat. No. 4,164,101 (1979) utilizes a shaft casing to connect the sanding head to a motor which supplies power to turn the head. This allows the sanding head to be separate from the motor and gives the operator more flexibility to operate the head.
However, the major drawback is the intense degradation which the shaft casing encounters during the sanding process. Some other system needs to be employed to reduce this friction such as a self-lubrication process.
Another arrangement, shown in Marton, U.S. Pat. No 4,058,936 (1977) attempts to increase the suction of finer debris by increasing the number of openings on the abrasive head or sanding disc. Although the increased suction surface area allows a wider area for collection, it results in diminishing suction capacity because the finer debris accumulates inside the motor and air lines causing the air volume to be reduced.
Cheng, U.S. Pat. No. 5,131,192 (1992) utilizes a dust arrester affixed to a hollow workbench by way of a tubular filter unit axially rotatable inside the workbench. The filter contains a blowing unit which generates the air stream to blow the collected dust into a dust bin. This system also results in diminishing suction capacity due to the accumulation of finer debris.